a BIG problem with a select statement

Hello guys i´m having troubles with this select statement:
What is exactly my trouble?
Well.
This script should returns me all the guys that i have in my database, but, it should also show me who is still using my services or not, it should show their children, wifes and parents situation too.
On that places where i´m using functions that returns me '1' or '0' if there are active values, i want it to force the select statement to put 'INACTIVE' or 'ACTIVE' instead of '1' or '0'.
every time the select find '1' or '0' it should return 'INACTIVE' or 'ACTIVE' acording with what i want it to do in that place of the statement, how can i do it?
Note that the function invert the values on some parts of the statement.

Thanks in advance

The select statement is below:

select *
from
(
SELECT
'BEN' AS KIND,
SUBSTR(SIS.sfn_SIT_MAN(a.COD_BEN, 1, TO_DATE('10/07/2003','dd/mm/yyyy')),1,65) AS SITUATION,
a.COD_BEN ,a.NAME ,a.BORNDT,
/* here is my trouble */
(DECODE(sis.pcg_serv_guy.sfn_est_ativ_usr(a.COD_BEN, TO_DATE('10/07/2003 23:59:59','dd/mm/yyyy hh24:mi:ss'),
a.COD_EMP),0,1,0))AS ACTIVE,
/*This one above show me if there are
some guys still using my services, it returns 0=INACTIVE 1=ACTIVE*/

(DECODE(sis.pcg_serv_guy.sfn_est_ativ_usr(a.COD_BEN, TO_DATE('10/07/2003 23:59:59','dd/mm/yyyy hh24:mi:ss'),
a.COD_EMP),0,0,1))AS INACTIVE
/*This one above show me if the guys aren´t using my services, it returns 0=ACTIVE 1=INACTIVE*/
FROM
SIS.GUYS_TABLE a

UNION

SELECT
'DEP' AS KIND,
SUBSTR(SIS.SIS.sfn_SIT_MAN(a.COD_DEP, 2, TO_DATE('10/07/2003','dd/mm/yyyy')),1,65) AS SITUATION,
a.COD_DEP,a.NAME,a.BORNDT,
/* here is my trouble */
(DECODE(sis.pcg_serv_guy.sfn_est_ativ_usr(a.COD_DEP, TO_DATE('10/07/2003 23:59:59','dd/mm/yyyy hh24:mi:ss'),
a.COD_EMP),0,1,0)) AS ACTIVE,

/*This one above show me if there are
some guys´s children still using my services, it returns 0=INACTIVE 1=ACTIVE*/

(DECODE(sis.pcg_serv_guy.sfn_est_ativ_usr(a.COD_DEP, TO_DATE('10/07/2003 23:59:59','dd/mm/yyyy hh24:mi:ss'), a.COD_EMP),0,0,1)) AS INACTIVE

/*This one above show me if the guys´s children aren´t using my services, it returns 0=ACTIVE 1=INACTIVE*/

FROM

SIS.GUYS_CHILD_WIVES_TABLE a,
SIS.HUSB_WIFES b

WHERE
a.COD_HUSB_WIFES = b.COD_HUSB_WIFES (+)
AND
b.MARRIED <> 'T'

UNION

SELECT

'HW' AS KIND,
SUBSTR(SIS.sfn_SIT_MAN(a.COD_DEP, 2, TO_DATE('10/07/2003','dd/mm/yyyy')),1,65) AS SITUATION,
a.COD_DEP,a.NAME,a.BORNDT,

/* here is my trouble */

(DECODE(sis.pcg_serv_guy.sfn_est_ativ_usr(a.COD_DEP, TO_DATE('10/07/2003 23:59:59','dd/mm/yyyy hh24:mi:ss'),
a.COD_EMP),0,1,0)) AS ACTIVE,

/*This one above show me if there are
some guys´s wifes,parents...etc still using my services, it returns 0=INACTIVE 1=ACTIVE*/

(DECODE(sis.pcg_serv_guy.sfn_est_ativ_usr(a.COD_DEP, TO_DATE('10/07/2003 23:59:59','dd/mm/yyyy hh24:mi:ss'), a.COD_EMP),0,0,1)) AS INACTIVE

/*This one above show me if the guys´s wifes,parents... aren´t using my services, it returns 0=ACTIVE 1=INACTIVE*/

FROM
SIS.GUYS_CHILD_WIVES_TABLE a,
SIS.HUSB_WIFES b
WHERE
a.COD_HUSB_WIFES = b.COD_HUSB_WIFES (+)
AND
b.MARRIED = 'T'
order by 1, 2)